@mixin block($block) {
  .ais-#{$block} {
    @content;
  }
}

@mixin element($element) {
  &--#{$element} {
    @content;
  }
}

@mixin modifier($modifier) {
  &__#{$modifier} {
    @content;
  }
}

@mixin bem($block, $element, $modifier: "") {
  @include block($block) {
    @include element($element) {
      @if $modifier != "" {
        @include modifier($modifier) {
          @content;
        }
      } @else {
        @content;
      }
    }
  }
}
